1. Field of the Invention
The present invention relates to a polyarylene sulfide resin composition, and more particularly, to a polyarylene sulfide resin composition having superior adhesion properties to an adhesive of epoxy resins or the like.
The present invention also relates to a container for accommodating electronic-component material and to an electronic component, and more particularly, to a container for accommodating electronic-component material which is molded from a polyarylene sulfide resin composition having superior adhesion properties with respect to a sealant for sealing a conductive portion of the electric component material, as well as to an electronic component whose conductive portions are sealed by a sealant encapsulated in the container.
2. Related Art
Polyarylene sulfide resin (hereinafter often referred to as "PAS resin") is an engineering plastic possessing heat resistance, fire resistance, electrical characteristics, or various superior mechanical and physical properties and is expected to be widely used in various fields of, e.g., mechanics, electricity, electronics, or automotive parts. Although there is a case where PAS resin having superior characteristics such as those mentioned previously is solely used, PAS resin is also used in the form of a laminated composite material containing another material, such as another resin, ceramics, or metal, or in the form of a laminated composite material containing other types of PAS resin of different performance characteristics, with a view to further improving the performance of PAS resin.
Such a composite material is manufactured by laminating PAS resin and another material with an adhesive composed of, e.g., epoxy resins, silicone resins, or urethane resins. In such a case, a composite material of insufficient adhesive strength may be produced, because it is hard to bond PAS resin itself to such an adhesive. For example, a known method of improving the adhesive strength between PAS resin and the adhesive comprises: a method of increasing the surface area of PAS resin by formation of minute channels in the surface of base material made of PAS resin through use of mechanical means such as friction; a method of deteriorating the surface of PAS resin by partial corrosion of the surface; and a method of priming the surface of PAS resin with a chemical primer. Another known method is one by which PAS resin is alloyed with another resin such as a thermoplastic resin, e.g., a high-water-absorptive resin led by polyacrylates, or by mixing PAS resin with an additive.
However, under the method of improving adhesion properties of PAS resin to an adhesive by treating the surface of PAS resin, there occurs an increase in the number of processes required for manufacturing a composite material. Further, depending on the type of PAS resin, a sufficient bonding effect is not always attained. For example, it is difficult to manufacture from PAS resin a composite material which is used under conditions where high temperature and constant vibrations are encountered and which is required to have adhesion properties to a specific resin such as an epoxy resin. Further, in a case where PAS resin is used for manufacturing a container for accommodating electronic-component material, since PAS resin has insufficient adhesion properties with respect to a sealant (such as epoxy resin), used for sealing conductive portions of each electronic-component material to be accommodated in the container, a minute clearance arises between the container made of PAS resin and the sealant, thereby posing problems such as electric discharge or a degradation in the electrical characteristics of the electronic-component material as a result of entry of moisture into the electronic-component material. There is also another problem of the container made of PAS resin itself being separated or exfoliated from the contents of the container.
Since most thermoplastic resins capable of improving the adhesion properties of PAS resin with respect to an adhesive have lower heat resistance than that of PAS resin, the method of mixing thermoplastic resin with PAS resin brings about a degradation in heat resistance of PAS resin--a characteristic feature of PAS resin--thus further resulting in a considerable reduction in mechanical strength of PAS resin. Particularly, in a case where PAS resin is used for manufacturing a container for accommodating electronic-component material, the adhesion properties of PAS resin with respect to a sealant are improved to a certain extent. However, since the heat resistance of PAS resin decreases, there arises a new problem of PAS resin becoming decomposed and generating gas or a new problem of the container becoming cracked as a result of a decrease in the mechanical strength of PAS resin. As things stand now, there has not yet been produced any substance which improves various superior characteristics of PAS resin and which possesses superior adhesion properties with respect to a sealant in a case where PAS resin is used for manufacturing a container for accommodating electronic-component material.
Further, depending on applications, there is strong demand for development of PAS resin possessing superior adhesion properties with respect to an adhesive made of, e.g., silicone resins other than epoxy resins or urethane resins.